| 摘要 |
<p>PURPOSE:To recover calcium carbonate and hydrogen sulfide by decomposing gypsum formed in the desulfurization of stack gas by a dry lime process in a high-temp. reducing gas. CONSTITUTION:Micron-particles of lime are atomized into the high-temp. combustion gas in a boiler 1, and allowed to react with sulfur oxide. The formed anhydrous gypsum is removed from the stack gas along with unreacted lime and dust in a dust collector 4. The recovered dust is separated by a classifier 8 into fine powder contg. anhydrous gypsum and unreacted lime in abundance and powder consisting essentially of ash. The fine powder is atomized into a high-temp. has contg. hydrogen and carbon monoxide, and reduced to calcium sulfide. Said gas is then cooled, and the calcium sulfide is allowed to react with gaseous carbon dioxide and steam to obtain calcium carbonate and hydrogen sulfide. The fine powder of calcium carbonate is separated from the gas in a dust collector 16, and reused as a desulfurizing agent. Hydrogen sulfide is recovered from the remaining gas.</p> |
